Air directing apparatus



A. BIBER EIAI.

AIR DIRECTING APPARATUS 2 Sheets-Sheet 1 Sept. 26, 1961 Filed Nov. 17,1958 M a r m u A Sept. 26, 1961 A. BIBER ETAI.

AIR DIRECTING APPARATUS 2 Sheets-Sheet 2 AZJERI' 8/85? Eel/Ff 2. W415.ATTO RIJEY United States Patent G t 2 3,001,576 v AIR DIRECTINGAPPARATUS H Albert Biber, Penn Hills Township, Allegheny County, andBruce R. Walsh, Wilkinsburg, Pa., assignors to Gulf Research &Development Company, Pittsburgh, Pa., a corporation of Delaware FiledNov. 17, 1958, Ser. No. 774,418

9 Claims.- (Cl. 158-76) This invention relates to an air directingdevice for gun-type fuel oil burners and more particularly to a devicefor attachment to the nozzle end of the air blast tube of gun-type fueloil burners. In gun-type fuel burners, liquid fuels are supplied to acombustion chamber generally in the form of a conical spray. Some meansis necessary to provide a supply of air or oxygen to the atomized fuelin order to produce combustion of said fuel.

The present invention provides a novel device for mixing the atomizedfuel and air to bring about more perfect combustion of the fuel.

The device of the invention is adapted for mounting over the nozzle andof the air blast tube of a gun-type fuel burner, and comprises a platehaving a relatively large central orifice in which the fuel nozzle islocated and a plurality of orifices surrounding said central orifice sooriented to direct jets of air into the fuel spray cone in order toinsure maximum mixing of the air While combustion takes place.

The invention is illustrated in the drawingsaccompanying thespecification and forming a part thereof and in which:

FIGURE 1 is a side elevation partially broken away of a gun-type fuelburner and shows the relative location of its various parts includingthe improved air injector of the invention.

FIGURE 2 is an end elevation of the improved air direction means of theinvention when attached to the nozzle end of the air blast tube. i

FIGURE 3 is a sectional view of FIGURE 2 taken along the line IIIHI.

FIGURE 4 is a sectional view of FIGURE 2 taken along the line IVIV.

FIGURE 5 is a sectional view of FIGURE 2 taken along the line V-V.

FIGURE 6 is a modified structure of the air direction means of theinvention when attached to the nozzle end of the air blast tube.

FIGURE 7 is a sectional view of FIGURE 6 taken along the line VII-VII,

Referring to FIGURE 1, the air directing means of this inventioncomprises a plate 11 which is adapted for mounting over the nozzle endof air blast tube 12 of guntype fuel burner 13. Plate 11 is adapted tobe frictionally held in position within the air blast tube 12. Otherfastening means, as for example, set screws can be employed for holdingthe plate in position. Fuel nozzle 14 with its fuel supply tube islocated centrally of air blast tube 12 and is approximately flush withthe front face of plate 11. The liquid fuel issues from fuel nozzle 14as a conical spray as at 15. In the embodiment shown, the air blower 16is located at the rear end of air blast tube 12 and projects the airthrough the blast tube into the combustion chamber as indicated by thearrows in FIGURE 1.

In FIGURE 2 numeral 11 again designates the entire air directing meansof this invention. Numeral 17 designates the relatively large centralcircular opening in which fuel nozzle 14 is located. Openings 18 and 19are provided to receive insulated electrodes (not shown) which serve thepurpose of igniting the liquid fuel which is atomized and dischargedinto the combustion chamber.

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2 Located on each side of central orifice 17 are openings 20 and 21. Asbrought out in FIGURE 5, orifices 20 and 21 are disposed in plate 11 atan angle with respect to the axis of the center orifice, to directconverging jets of air toward the fuel spray cone so as to impinge uponand penetrate the fuel spray cone. The side orifices are preferablyinclined inwardly at an angle of approximately 30 more or less to theaxis of the center orifice 17.

As shown also in FIGURE 5, the rear portions of orifices 20 and 21 areflared as at 22 to present a relatively large air intake area and asomewhat more restricted discharge outlet. This structure tends toimpart greater velocity to the jet of air leaving the orifices andassists the air in penetrating the fuel spray cone and interminglingwiththe atomized fuel. Numeral 23 designates a relatively elongated slotpositioned above the central orifice 17 through which a relatively broadstream of air is discharged into the combustion zone. As shown in FIG-URE 3, deflector 24 extends outwardly from plate 11 above slot 23 forthe purpose of directing the air stream which is'discharged through slot23. The deflector 24 is provided with a downwardly projecting tip as at25 which structure insures that the air stream emerging from slot 23does not diverge upwardly from the fuel cone.v Numeral 26 designatesanother somewhat smaller elongated slot located below the centralorifice 17 through which a portion of the air is discharged. As shownalso in FIG- URE 3, lip 27 extends from plate 11 below slot 26 and isinclined upwardly to define with the face of plate 11 an angle ofapproximately 30 in order to direct a stream of air upwardly into thefuel cone. A distinctive feature of this arrangement is that the air isdirected through the various orifices in a manner to penetrate the fuelcone at a plurality of points thus insuring that a supply of air isavailable throughout the fuel spray cone. In addition; by means of thedescribed arrangement a curtain of air is supplied above the flame whichcauses the fiarne to be confined and provides an additional supply ofair to insure more complete combustion.

The over-all size of the plate comprising the air direct ing device ofthe invention will depend upon the size of the air blast tube of the gunburner in which it is to be used. For example with a gun-type burnerhaving a blast tube 4 inches in diameter the plate 11 will beconstructed so as to have a diameter of slightly less than 4 inches topermit it to be inserted and held within the discharge end of the blasttube. The size of the various orifices provided in plate .11 will varywith the volume of the combustion space and with the amount of oil to beburned. By way of example, the following size orifices have provedfeasible for use in a gun-type burner equipped with a fuel nozzledelivering gallon of fuel per hour. The center orifice 17 is made largeenough the accommodate a conventional fuel nozzle and will be forexample, approximately inch in diameter and the side orifices 20 and 21approximately /8 inch in diameter. The lower elongated slot 26 isapproximately inch by 1 /4 inches and the upper elongated slot 23 isapproximately inch by 1% inches. When burning larger amounts of oil theair supply will, for proper combustion be greater and the size of theorifices will be correspondingly increased.

In FIGURES 6 and 7, there is shown a preferred em' bodiment of theinvention wherein the side inwardly projecting orifices are carried in astrip 28 which is attached to the front face of plate 11 by means ofscrews 29. In this embodiment of the invention the side orifices 20 and21 are disposed in plate 11 parallel with the axis of the centralorifice 17, thus simplifying manufacture of the plate 11. To obtain theeffect of the side air streams converging toward the fuel cone, strip 28is provided with two inwardly projecting side orifices 30 and 31 .mentof the invention, it is a simple matter to replace the .strip member 28with one in which the side orifices are of larger size to compensate forany change in the amount of fuel being supplied to the combustionchamber as would occur upon substitution of a fuel nozzle of greatercapacity.

In operation of the air directing device of the invention, air fromblower 16 travels down air blast tube 12 to plate 11. The relativelylarge stream of air is broken up at this point into a number of air jetsof shapes corresponding to the configuration of the various orifices inthe plate. A minor portion of the air passes through center hole '17around fuel nozzle 14 and performs the function of creating an initialspray of oxygen for the combustion of the atomized fuel emerging fromnozzle 14. A larger blast of air passes through the lower slot- Iikeopening 26 and. is directed upwardly by lip 27 to encounter the fuelcone at a point relatively near the fuel nozzle. The .side orifices 29and 21 deliver 'two high velocity jets of air which 'impinge'upon thefuel cone at a point farther away from the fuel nozzle to support alater stage of combustion. The upper elongated slot 23 discharges arelatively broad sheet-like curtain of air over the flame which supportsfurther combustion and in addition causes the flame 'to be confined.Thus, by means of the air directing device of the invention, air iscaused to surround and penetrate the fuel cone and a thoroughintermingling of the fuel and air is insured. Moreover, substantiallyall of the air comes into contact with the burning oil and gases duringcom bustion so that it is unnecessary to provide an excessive amount ofair which will tend to reduce the temperature and efliciency in order tosecure clean and complete combustion.

Asis apparent, a gun-type fuel burner equipped with the; air directingdevice of the invention can be utilized to supply a mixture of fuel andair toany conventional combustion chamber. The principal advantageproduced by this invention is that of improved combustion efficiency.Tests have proven that the use of the air directing device of thisinvention results in a blue fiame within the combustion chamber andcombustion products having low smoke numbers and'high carbon dioxidecontent.

'Thosemodifications and variations which fall within the spirit of theinvention and the scope ofthe appended claims are to be considered partof the invention.

We claim: 1. An air directing device for use in fuel burners comprisinga plate having a relatively large central orifice through which asubstantially conical spray of fuel is delivered to a combustion zone,said plate having an elongated horizontally extending slot-like openinglocated above said central orifice and means in said plate including aplurality of orifices adjacent said central orifice having their axesdisposed at an angle .to the axis of said central orifice for deliveringa plurality of forwardly converging streams of air which'irnpinge'uponthe said fuel spray.

2. An air directing device forum in fuel burners comprising a platehaving .a relatively large central orifice through which .asubstantially conical spray of-fuel .is delivered to a combustion zone,said plate having an elongated horizontally extending slot-like openinglocated above said central orifice through which a stream of airisdelivered above said fuel spray, said plate having asecond elongatedhorizontally extending slotlike opening 10-- cated below said cenualorifice through which a stream of air is supplied for combustion of thefuel, a lip member extending outwardly and upwardly from below said lastmentioned opening to direct the air emerging therefrom so that itimpinges upon the .said fuel spray, said plate having openings locatedon opposite .sides of said central orifice and disposed at an angle tothe axis thereof for .de; livering a plurality of forwardly convergingstreams of air which impinge upon the said fuel spray.

3. An air directing device for use in fuel burners comprising a platehaving .a relatively large central orifice through which a substantiallyconical spray of fuel is delivered to .a combustion zone, said platehaving an elongated horizontally extending slot-like opening locatedabove said central orifice and axially paralled thereto through which astream of air is delivered above said fuel spray, a deflectormemberlocated above said elongated opening and extending outwardly fromthe face of said plate and being provided with a downwardly projectingtip, said plate having a second elongated horizontally extendingslot-like opening located below said central orifice through which astream of air is supplied for combustion of'said fuel, a lip memberextending outwardly and upwardly from below said last-mentioned openingto direct thelair stream emerging therefrom so that it impinges uponsaid fuel spray, said plate having openings located on opposite sides ofsaid central orifice and disposed at an angle to the axis thereof todeliver a plurality of forwardly converging streams of air which impingeupon said fuel spray. 7

4. An air directing device for use in fuel burners com prising a platehaving a relatively large central orifice through which a substantiallyconical spray of fuel is delivered to a combustion zone, said platehaving an elongated horizontally extending slot-like opening locatedabove said central orifice and axially parallel thereto through which arelatively broad sheet-like stream of air is delivered above said fuelspray, said plate having a second elongated horizontally extendingslot-like opening located below said central orifice through which astream ofairissupplied for combustion of said fuel, a lipmembeiextending outwardly and upwardly from below said last-mentionedopening to direct the air emerging there from so that it impinges uponthe said fuel spray at a point relatively near the face of said plate,said plate having two openings located on opposite sides of said centralorifice and disposed at an angle to the axis thereof to deliver twoforwardly converging streams of air which impinge upon the said fuelspray at a point spaced for wardly from the face of said plate. g

5. An air directing device for use in fuel burners com-f prising a platehaving a relatively large central orifice through which a substantiallyconical spray of fuel is delivered to a combustion zone, said platehaving an elongated horizontally extending slot-like opem'ng locatedabove said central orifice and axially parallel thereto through which astream of is delivered above said 'fuel spray, a deflector memberlocated above said elongated opening and extending outwardly from theface of the said plate and being provided with a downwardly projectingtip, said plate having a second elongated hori zontally extendingslot-like opening located below said; central orifice through which astream of air is supplied for the combustion of said fuel, a lip memberextending outwardly and upwardly from below said last-mentioned openingto direct the air stream emerging therefrom so that it impinges uponsaid fuel spray, said platehaving two circular openings located onopposite sides of the said central orifice and axially parallel thereto,a strip member extending transversely across the front face of saidplate and removably attached thereto, said strip member having a centralorifice matching said central: orifice in said plate, said .strip memberhaving also two orifices disposed on opposite sides of the centralorifice and spaced tomatch :thetwo circular side :openingswith-i in saidplate, the side orifices within said strip member being disposed at anangle to the axis of the central orifice of said plate, to deliver twoforwardly converging streams of air which impinge upon said fuel sprayat a point spaced forwardly from the face of said plate, said stripmember having also a recess in the inner face thereof extendinglaterally from the central orifice to the side orifices therein.

6. In combination with a fuel burner having an air blast tube and burnernozzle which delivers a fuel spray, an air directing device comprising aplate which is adapted for mounting over the discharge end of said airblast tube, said plate having a relatively large circular orificelocated centrally of said plate in axial alignment with said nozzle,said plate having an elongated horizontally extending slotlike openinglocated above said central orifice and means within said plate includinga plurality of orifices surrounding said central orifice having theiraxes disposed at an angle to the axis of said central orifice fordelivering a plurality of forwardly converging streams of air whichimpinge upon the said fuel spray.

7. In combination with a fuel burner having an air blast tube and burnernozzle which delivers a fuel spray, an air directing means comprising aplate mounted over the discharge end of said air blast tube, said platehaving a relatively large circular orifice located centrally of saidplate in axial alignment with said nozzle, said plate having anelongated horizontally extending slot-like opening located above saidcentral orifice through which a stream of air is delivered above saidfuel spray, said plate having a second elongated horizontally extendingslot-like opening within said plate located below said central orificethrough which a stream of air is supplied for combustion of the fuel, alip member extending outwardly and upwardly from said plate below saidlast-mentioned opening to direct the air emerging therefrom so that itimpinges upon the said fuel spray, said plate having openings locatedwithin said plate on opposite sides of said central orifice and disposedat an angle to the axis thereof for delivering a plurality of forwardlyconverging streams of air which impinge upon the said fuel spray.

8. In combination with a fuel burner having an air last tube and burnernozzle which delivers a fuel spray, an air directing means comprising aplate mounted over the discharge end of said air blast tube, said platehaving a relatively large circular orifice located centrally of saidplate in axial alignment with said nozzle, said plate having anelongated horizontally extending slot-like opening located above saidcentral orifice and axially parallel thereto through which a stream ofair is delivered above said fuel spray, a deflector member located abovesaid elongated opening and extending outwardly from the face of saidplate and being provided with a downwardly projecting tip, said platehaving a second elongated horizontally extending slot-like openingwithin said plate located below said central orifice through which astream air is supplied for combustion of said fuel, a lip memberextending outwardly and upwardly from below said last-mentioned openingto direct the air stream emerging therefrom so that it impinges upon thesaid fuel spray, said plate having openings located said plate onopposite sides of said central orifice and disposed at an angle to theaxis thereof to deliver a plurality of forwardly converging streams ofair which impinge upon said fuel spray.

9. in combination with a fuel burner having an air blast tube and burnernozzle which delivers a fuel spray, an air directing means comprising aplate mounted over the discharge end of said air blast tube, said platehaving a relatively large circular orifice located centrally of saidplate in axial alignment with said nozzle, said plate having anelongated horizontally extending slot-like opening within said platelocated above said central orifice and axially parallel thereto throughwhich a stream of air is delivered above said fuel spray, a deflectormember located above said elongated opening and extending out wardlyfrom the face of the said plate and being provided with a downwardlyprojecting tip, said plate having a second elongated horizontallyextending slot-like opening within said plate located below said centralorifice through which a stream of air is supplied for the combustion ofsaid fuel, a lip member extending outwardly and upwardly from said platebelow said last-mentioned opening to direct the air stream emergingtherefrom so that it impinges upon said fuel spray, said plate havingtwo circular openings located on opposite sides of the said centralorifice and axially parallel thereto, a strip member extendingtransversely across the front face of said plate and removably attachedthereto, said strip member having a central orifice matching saidcentral orifice in said plate, said strip member having also twoorifices disposed on opposite sides of the central orifice and spaced tomatch the two circular side openings Within said plate, the sideorifices within said strip member being disposed at an angle to the axisof the central orifice of said plate, said strip member having also arecess in the inner face thereof extending laterally fiom the centralorifice to the side orifices therein.

References Cited in the file of this patent UNITED STATES PATENTS1,911,488 Blatter May 30, 1933 1,976,097 Sharp Oct. 9, 1934 2,253,414Arnold Aug. 19, 1941 2,500,787 Lelgemann Mar. 14, 1950 2,694,444Oldenkamp Nov. 16, 1954 FOREIGN PATENTS 47,814 Denmark Sept. 25, 1933

